[1] Univ Cent Hosp, Dept Obstet & Gynecol, Helsinki, Finland
[2] HUSLAB Lab Serv, Coagulat Unit, Dept Hematol, Helsinki, Finland
[3] HUSLAB Lab Serv, Coagulat Unit, Dept Clin Chem, Helsinki, Finland
[4] Turku Univ, Dept Med, Pori, Finland
[5] Satakunta Cent Hosp, Pori, Finland